Shoe insole

ABSTRACT

An insole easy to wash and excellent in adhesiveness to the sole of a shoe is provided. An insole produced by punching a piece of the shape of a sole of a shoe or the shape of the leading terminal of a sole of a shoe out of a thermoplastic elastomer by the injection molding technique.

TECHNICAL FIELD

This invention relates to an insole and particularly to an antifouling sheet for sandals such as sandals and sandal mules.

BACKGROUND ART

The insoles have been used hitherto on the sole parts of sandals such as sandals and sandal mules with a view to preventing defilement, imparting a cushioning property to such a sandal, and preventing slippage of the wearer's foot on the sandal. As the insoles suitable for such purposes, the products resulting from punching pieces of prescribed shapes (the shapes of the whole undersurfaces of shoes or the shapes of the toe cap parts of shoe soles, for example) out of a sheet as of a silicone rubber have been being mainly used.

Since these insoles are made of silicone rubber, however, they have been at a disadvantage in affording insufficient adhesion to the soles of shoes and consequently, during the course of use, suffering themselves to be displaced or rolled up. Particularly when they have the shape of toe caps of the soles of shoes as in sandals for use by women, they are at a disadvantage in being displaced or rolled up because the soles are exposed to a large load and frictional force while the users' feet are being inserted into the toe caps.

An object of this invention, therefore, is to provide a novel insole.

Another object of this invention is to provide an antifouling sheet particularly for a sandal, which affords a proper adhesion to the sole of a shoe and avoids being displaced or peeled on exposure to a large load and frictional force.

DISCLOSURE OF THE INVENTION

The objects mentioned above are accomplished by the following items (1)-(6).

(1) An insole produced by molding a thermoplastic elastomer into a sheet in the shape of a shoe sole or the shape of a toe cap of a shoe by the injection molding technique.

(2) An insole set forth in the preceding item (1), wherein the upper surface of the insole has undergone an embossing treatment.

(3) An insole set forth in the preceding item (2), wherein the protruding portions of the insole have escaped the embossing treatment.

(4) An insole set forth in any of the preceding items (1)-(3), wherein the insole is furnished with removable protrusions made of a thermoplastic elastomer.

(5) An insole set forth in the preceding item (4), wherein the protrusions are intended as a measure against hallux valgus.

(6) An insole set forth in the preceding item (4), wherein the protrusions are intended for correction of flat foot.

(7) An insole set forth in the preceding item (4), wherein the protrusions are intended for correction of knock-knees.

(8) An insole set forth in the preceding item (4), wherein the protrusions are intended for correction of bowlegs.

(9) An insole set forth in the preceding item (4), wherein the protrusions are intended for the absorption of shocks.

(10) An insole set forth in any of the preceding items (1)-(4), wherein the insole is a half insole.

(11) An insole set forth in the preceding item (10), wherein at least the foot-inserting side of the half insole is endowed with an inclination tapered in the direction of the surface.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a top view illustrating one preferred embodiment of the insole contemplated by this invention,

FIG. 2 is a top view illustrating another preferred embodiment of the insole contemplated by this invention,

FIG. 3 is a cross section taken through FIG. 2 along the line III-III,

FIG. 4 is a top view illustrating another preferred embodiment of the insole contemplated by this invention,

FIG. 5 is a top view illustrating still another preferred embodiment of the insole contemplated by this invention,

FIG. 6 is a cross section illustrating one preferred embodiment of the measure against hallux valgus to be used for the insole contemplated by this invention,

FIG. 7 illustrates one preferred embodiment of the insole for correction of flat foot according to this invention,

FIG. 8 is a cross section of a protrusion taken through FIG. 7 along the line VIII-VIII,

FIG. 9 illustrates one preferred embodiment of the insole for correction of knock-knees according to this invention,

FIG. 10 is a cross section of a protrusion taken through FIG. 9 along the line X-X,

FIG. 11 illustrates one preferred embodiment of the insole for correction of bowlegs according to this invention,

FIG. 12 is a cross section of a protrusion taken through FIG. 11 along the line XII-XII,

FIG. 13 illustrates one preferred embodiment of the insole intended for the absorption of shocks according to this invention, and

FIG. 14 is a cross section of a protrusion taken through FIG. 13 along the line XIV-XIV.

BEST MODE OF EMBODYING THE INVENTION

Now, this invention will be described in detail below with reference to the annexed drawing.

Specifically, insoles land 2 according to this invention, as illustrated in FIG. 1 and FIG. 2 (invariably illustrating only the left foot), are in a shape 1 substantially identical with the shape of the entire sole of a shoe and in a (half insole) shape 2 of the leading terminal of a sole of a shoe (the portion forward from the roots of toes). Then, the surface of the insole (the surface opposite the surface contacting the sole of a shoe) is in a delustered state resulting from an embossing treatment and is consequently enabled to manifest an effect of proofing the surface contacting the foot against slippage.

The insole is obtained by forming a thermoplastic elastomer in the shape of a sole of a shoe (refer to FIG. 1) or in the shape of a leading terminal of a sole of a shoe (the forward portion from the roots of toes) (refer to FIG. 2) by the injection molding technique. In this case, the surface (namely the surface opposite the surface contacting the sole of a shoe) is preferred to be in a delustered state resulting from an embossing treatment. This embossing treatment may be carried out simultaneously with the injection molding treatment by endowing an embossing surface in advance on a metal die used for the injection molding treatment. As a result, an insole having an embossed contour on one of the opposite surfaces thereof is obtained. The thermoplastic elastomer optionally may have a metal powder or a metal foil such as, for example, aluminum powder, aluminum foils, copper powder, or copper foils dispersed therein so as to assume a laminar texture. The laminar texture adds to the beauty of the insole and enhances the fashionableness thereof.

In contrast, the undersurface (the surface contacting the sole of a shoe) of the insole is flat because it has not undergone the embossing treatment. When it is pressed during the course of use as described herein below, it affords unusually proper adhesion to the sole of a shoe.

The thickness of the insole 1 or 2 falls in the range of 0.4-1.2 mm, preferably in the range of 0.4-0.9 mm, and more preferably in the range of 0.4-0.7 mm. When the insole has the shape (half insole) 2 of the leading terminal of the sole of a shoe as illustrated in FIG. 2, at least an end face 3 on the side opposite the toe tips is preferred to possess an inclination tapered in the direction of the surface as illustrated in FIG. 3. When the insole is pressed during the insertion of a foot into a sandal, therefore, the foot is smoothly inserted without displacing the insole.

When the embossing treatment is not performed in part of an insole 4, 5, particularly the portion destined to mount a protrusion as a measure against hallux valgus as specifically described herein below, as illustrated in FIG. 4 and FIG. 5, the portions 6, 7 (the portions for raising the protrusions) are transparent because of the absence of an embossing treatment (even when the embossing treatment has been given), the decision to fix a location for raising a protrusion 8 for preventing hallux valgus as illustrated in FIG. 6 is facilitated greatly. This protrusion 8 for the prevention of hallux valgus generally has a flat undersurface and a curved surface. The insoles 4, 5 and the protrusion for preventing hallux vlgus enjoy highly satisfactory mutual adhesion because they are both made of a thermoplastic elastomer. Once this protrusion is mounted at a prescribed position, therefore, it has no possibility of being displaced on being exposed to the sliding force or the pressing force during the insertion of a foot into the sandal.

An insole 9 illustrated in FIG. 7 has substantially the entire surface thereof in a delustered state in consequence of an embossing treatment excepting the arched part which forms a portion 10 having escaped the embossing treatment. On the portion which has escaped the embossing treatment, a protrusion 11 may be mounted removably. This protrusion 11, as illustrated in FIG. 8, has a flat undersurface and an upwardly curved surface. The protrusion of this contour is capable of correcting a flat foot.

An insole 12 illustrated in FIG. 9 has substantially the entire surface thereof in a delustered state in consequence of an embossing treatment excepting the inner side approximating closely to the ankle part which forms a portion 13 having escaped the embossing treatment. On the portion which has escaped the embossing treatment, a protrusion 14 is freely mounted removably. This protrusion 14 as illustrated in FIG. 10 assumes a shape gradually gaining in height in the direction of the inside. Owing to this contour, it is capable of correcting the knock-knees.

An insole 15 illustrated in FIG. 11 has substantially the entire surface thereof in a delustered state in consequence of an embossing treatment excepting the outer side approximating closely to the ankle part which forms a portion16 having escaped the embossing treatment. On the portion which has escaped the embossing treatment, a protrusion 17 is freely mounted removably. This protrusion 17 as illustrated in FIG. 12 assumes a shape gradually gaining in height in the direction of the outside. Owing to this contour, it is capable of correcting bowlegs.

Then, an insole 18 illustrated in FIG. 13 has substantially the entire surface thereof in a delustered state in consequence of an embossing treatment excepting the ankle part thereof which forms a portion 19 having escaped the embossing treatment. On the portion which has escaped the embossing treatment, a protrusion 20 is freely mounted removably. This protrusion 20 as illustrated in FIG. 14 has a substantially flat surface It is, therefore, capable of absorbing the load or the shock exerted to bear on the ankle of foot.

The curves indicated by the symbols a-c in FIG. 1, FIG. 4, FIG. 7, FIG. 9, FIG. 11, and FIG. 13 are lines for cutting the insole 1, 4 to fit the size of a given shoe.

The thermoplastic elastomer to be used in this invention is known in various types such as, for example, the polystyrene type, polyolefin type, polyurethane type, and polyester type. Among other types of thermoplastic elastomer enumerated above, the polyester type thermoplastic elastomer proves particularly favorable because it abounds in injection moldability, excels in adhesiveness, and capable of manifesting rubberiness at room temperature or lower temperature as well.

As concrete examples of the polyester ype thermoplastic elastomer, styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-butylene-styrene block copolymer (SEBS), and styrene-ethylene-propylene-styrene block copolymer (SEPS) may be cited. These polyester type thermoplastic elastomers are preferably used as molding materials (molding compounds) having such polyolefins as polypropylene and polyethylene compounded as with oils for exalting hardness and fluidity.

Such a thermoplastic elastomer generally as a molding compound is molded to produce an insole by the injection molding technique.

Now, this invention will be described more specifically below with reference to working examples.

EXAMPLE 1

A molding compound having a styrene-butadiene-styrene block copolymer (SBS) compound with polypropylene and oil (made by Kuraray Plastic K.K. and sold under the trademark designation of “Septon KC-145A”) and aluminum foils added thereto were together molded by an injection molding device (made by Sumitomo Jukikai K.K. and sold under the product code of “SG-75”), with a nozzle temperature of 250° C., a first zone temperature of 240° C., and a second zone temperature of 230° C. to form an insole of the shape illustrated in FIG. 4 and FIG. 5. The surface of this insole excepting the indicated part (the part indicated with reference numerals 6 and 7) was subjected to an embossing treatment. Consequently, a laminar insole 4, 5 having a thickness of 0.7 mm was produced. The portions indicated above (the reference numerals 6 and 7) were transparent.

A protrusion 8 for prevention of hallux valgus having a shape illustrated in FIG. 6 and measuring 30 mm in diameter and 4 mm in largest height was produced by using the same material and the same conditions.

The insole thus obtained, when laid on a sandal, manifested very satisfactory adhesiveness to the sole of the sandal and showed still better adhesiveness to the protrusion for prevention of hallux valgus. When a foot was inserted in the insole, this insole induced absolutely no displacement or separation. Since the portions 6, 7 for decision of position were transparent, the position of the protrusion 8 for prevention of hallux valgus could be determined very easily.

The half insole 5 illustrated in FIG. 5 induced absolutely no displacement or separation when a foot was inserted therein because the end face 3 of the side opposite the side of the leading paarts of toes (the side of the roots of toes) was in an inclined state tapered in the direction of the upper surface.

Industrial Applicability

The insole according to this invention is produced by injection molding a thermoplastic elastomer as described above. It, therefore, has no possibility of inducing displacement or separation when a foot is inserted therein on account of pressing force or sliding force. When the portion for mounting a protrusion for prevention of hallux valgus is clearly indicated, the location of this position is very easy. The mutual adhesion between the protrusion for preventing hallux valgus and the insole is highly satisfactory without use of any special adhesive agent. The insole, when subjected to an embossing treatment, is enabled to prevent slippage infallibly. When a portion having escaped the embossing treatment is formed as required and the protrusion is mounted on that portion, the adhesiveness of the protrusion is greatly exalted at that portion. Depending on the portion using the combination, the correction of a flat foot, knock-knees, and bowlegs can be easily effected.

Further, since this insole can be removed from the shoe easily when it becomes dirty. Thus, it can be kept clean at all times and can be prevented from odor. The insole of this invention can be formed by the injection molding technique. Thus, the letter L or R (not shown) for indicating the left side or the right side and the results of cutting (a, b, c) depending on the size of a shoe, and other necessary matters can be easily inscribed on the insole during the course of molding. 

1. An insole produced by molding a thermoplastic elastomer into a sheet in the shape of a shoe sole or the shape of a toe cap of a shoe by the injection molding technique.
 2. An insole according to claim 1, wherein the upper surface of said insole has undergone an embossing treatment.
 3. An insole according to claim 2, wherein the protruding portions of said insole have escaped said embossing treatment.
 4. An insole according to claim 1, wherein the insole is furnished with removable protrusions made of a thermoplastic elastomer.
 5. An insole according to claim 4, wherein said protrusions are intended as a measure against hallux valgus.
 6. An insole according to claim 4, wherein said protrusions are intended for correction of flat foot.
 7. An insole according to claim 4, wherein said protrusions are intended for correction of knock-knees.
 8. An insole according to claim 4, wherein said protrusions are intended for correction of bowlegs.
 9. An insole according to claim 4, wherein said protrusions are intended for the absorption of shocks.
 10. An insole according to claim 1, wherein the insole is a half insole.
 11. An insole according to claim 10, wherein at least the foot-inserting side of the half insole is endowed with an inclination tapered in the direction of the surface.
 12. An insole according to claim 2, wherein the insole is furnished with removable protrusions made of a thermoplastic elastomer.
 13. An insole according to claim 3, wherein the insole is furnished with removable protrusions made of a thermoplastic elastomer.
 14. An insole according to claim 2, wherein the insole is a half insole.
 15. An insole according to claim 3, wherein the insole is a half insole.
 16. An insole according to claim 4, wherein the insole is a half insole.
 17. An insole according to claim 12, wherein the insole is a half insole.
 18. An insole according to claim13, wherein the insole is a half insole. 